I've been getting them as well. Previous ones have been from "odd" email addresses, but I've had the same email twice this week from a sky.com address:
Hi there
I need a favour from you. I'd appreciate if you could email me back.
Yours sincerely.
Dennis Kenyon
I have been in touch with Dennis in the past, but even so, I replied with some questions for him that only he would know, but have received no reply.